C.31.  $world->getaliasnumber


$world->getaliasnumber function: GETs an ALIAS's NUMBER

@list = $world->getaliasnumber( name );

Returns a list with the number(s) of the alias(es) matching the given name. If no alias with that name is found, returns an empty list. If there are several aliases with the same name, returns the numbers of all of them.

The number of an alias is necessary to edit it. However, as the user can change the order of aliases, create new ones and delete old aliases, an alias's number may change, so you should not store its number; you must fetch the number just before editing it.